12v auxiliary battery charging

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londiniumperson
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Post by londiniumperson » Mon Dec 06, 2021 10:13 pm

Jan44 wrote:
Mon Dec 06, 2021 4:37 pm
I haven't had that problem, but I bought a neat little Lidl charger. My question is: Is ity essential/desirable to disconnect the battery from car before attaching charger?
I don't know either way, however I left the battery connected & I think if you use a quality charger with various types of protection like a CTEK, then I can't see why the battery needs to be disconnected, especially when CTEK sell connectors for permanent connection:

CTEK_Connect-eyelet.PNG

I use a CTEK MXS 5.0 (max 5 Amp) charger & just bought the 2.5m extension cable so hopefully I can leave the unit on the garage floor and charge the car outside for those days when it's raining (a car doesn't fit in my garage):

CTEK_Connect-extension.PNG

Last edited by londiniumperson on Wed Dec 08, 2021 10:23 pm, edited 1 time in total.
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advance2020
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Post by advance2020 » Wed Dec 08, 2021 9:42 am

There is much on the Forum already on this Topic, because it is obviously very important to have 12V in good health. However unlike an ICE car, it doesn't take much stored energy to wake up your car.
1. It is relatively easy to drain your 12V by using power for long periods while stationary. Vacuuming your car, with radio on etc. Dealers have done it as well! Just be aware your Main Battery won't “top up” the 12V unless the car is “Powered Up”.
2. Despite what the Manual says, many of us have successfully used a Battery Charger to top up 12V. My car is garaged, and I have yet to not use the car for more 3-4 days, so 12V battery drain has never been a problem.
3. If you are concerned, there are Power Bank solutions - checkout MrEV on YouTube and more on this Forum. So it is possible to Start your car with a dead 12V battery. Handy device to have. Let's hope you never need to use it.
Last edited by advance2020 on Thu Dec 09, 2021 4:08 pm, edited 1 time in total.
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advance2020
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Post by advance2020 » Thu Dec 09, 2021 4:06 pm

Oh dear. I should NOT have tempted fate, with my Post yesterday. It prompted me to check the voltage of my 12V battery. It was low at 11.58V so I decided I should re-charge it. So I connected by Halfords battery charger, as I had done before, but it went bang. The 20A fuse in the charger blew. And then my car went into MELTDOWN mode. Lots of strange noises, flashing lights, esp. rear Red ones. It was not happy. Was unable to Power Up, or move the car. Couldn't lock it with remote, and eventually it went to sleep, or had it died? What had I done!!!

I called my Dealer, who advised me to call Hondacare Assistance 0800 521 728
The AA responded quickly, even though my car was in our garage. And the guy sorted it. Very thorough and professional. Lots of checks etc. The battery voltage was down to 4.5V and something was drawing 4 amps, although the car seemed to have everything switched off. And at one point, after recharging the 12V he could measure a 20A draw. This was when I closed the Drivers side window, using the remote.

He provided a new 20A fuse, and we left it trickle charging overnight. Battery now at 12.75V And it held up OK today. A trip out to Shepton Mallet, in part to thank my Dealer. Fingers crossed, this is a one off. Maybe I'll ask Santa for one of those Power Bank things.
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ChesterUK
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Post by ChesterUK » Fri Dec 10, 2021 8:00 am

So my wife contacted the dealer and they asked to have the car dropped in for a check. They didn't find any abnormally high current drain, but topped up the battery and noticed there has been a software update that fixes a known issue with current draw and applied it.

My advice, if you are concerned about this and haven't had a service in a while and it's a fair time until the next one is due, contact your dealer.

Honda: Over the air updates would have solved this for a lot of people without a dealer visit. So now you know why you need to do it!

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Post by BarryG » Thu Mar 17, 2022 6:19 pm

I was concerned about the condition of my 12 volt battery, having read reports of sudden failures and the fact that the battery warning light only comes on when the battery is already flat.
I decided to fit a voltage monitor to the battery. The unit is designed to monitor motor home batteries, but work on any battery. Go on Amazon and search Battery Monitor BM.
It comes with an app for either Android or Apple.
The monitor connects to the app via Bluetooth when you open the app within about 3 meters of the battery.
The unit records battery voltage continually. You are able to see how the battery voltage fluctuates.
I have noted regular small loads appearing which drop the voltage slightly for a few secounds.
No ideal what what those loads are. The increase in voltage indicate the charge periods.
See screen shots attached [img][/

C4C480A0-FB1B-4588-882E-915373426602.jpeg

E9F35CED-6590-465A-82AD-44A99490357C.jpeg

img]

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advance2020
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Post by advance2020 » Thu Mar 31, 2022 11:00 am

londiniumperson wrote:
Mon Dec 06, 2021 10:13 pm
Jan44 wrote:
Mon Dec 06, 2021 4:37 pm
I haven't had that problem, but I bought a neat little Lidl charger. My question is: Is ity essential/desirable to disconnect the battery from car before attaching charger?
I don't know either way, however I left the battery connected & I think if you use a quality charger with various types of protection like a CTEK, then I can't see why the battery needs to be disconnected, especially when CTEK sell connectors for permanent connection: CTEK_Connect-eyelet.PNG

I use a CTEK MXS 5.0 (max 5 Amp) charger & just bought the 2.5m extension cable so hopefully I can leave the unit on the garage floor and charge the car outside for those days when it's raining (a car doesn't fit in my garage):
CTEK_Connect-extension.PNG
I was reluctant to DISCONNECT 12V but now believe it is wise to do so*.
Having had 3 failures, and called for AA assist twice, I am better informed.
1. My Dealer says “always lock your car”
2. AA also recommend locking your car (even if garaged) and disconnect battery before charging -ve lead is easiest.
3. Disconnecting does no harm. Car will tell “Audio System has been switched off” reset to get screens working again.
4. But be careful with Drivers door, as window doesn't drop, when you open door with no power.

*not sure why but one time I tried to charge 12V with leads connected, my Battery Charge blew a 20A fuse and my car went into meltdown. All matter of alarms, flashing lights etc and then it totally died.
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AVG economy and Predicted Mileage has increased lately, not sure why.

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advance2020
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Post by advance2020 » Thu Mar 31, 2022 11:13 am

BarryG wrote:
Thu Mar 17, 2022 6:19 pm
I was concerned about the condition of my 12 volt battery, having read reports of sudden failures and the fact that the battery warning light only comes on when the battery is already flat.
I decided to fit a voltage monitor to the battery. The unit is designed to monitor motor home batteries, but work on any battery. Go on Amazon and search Battery Monitor BM.
It comes with an app for either Android or Apple.
The monitor connects to the app via Bluetooth when you open the app within about 3 meters of the battery.
The unit records battery voltage continually. You are able to see how the battery voltage fluctuates.
I have noted regular small loads appearing which drop the voltage slightly for a few secounds.
No ideal what what those loads are. The increase in voltage indicate the charge periods.
See screen shots attached [img][/C4C480A0-FB1B-4588-882E-915373426602.jpegE9F35CED-6590-465A-82AD-44A99490357C.jpegimg]
Thanks BarryG
This link to MrEV might be helpful for others Battery Monitor BM2

I have now fitted one. Very useful as it shows State of Charge. If your 12V is giving problems, get a BM2 and/or get your Dealer to test your battery. They have a standard test.
Last edited by advance2020 on Thu Apr 21, 2022 1:15 pm, edited 1 time in total.
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AVG economy and Predicted Mileage has increased lately, not sure why.

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advance2020
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Post by advance2020 » Thu Apr 21, 2022 1:12 pm

Scanning through some of these posts, I see many are having problems with 12V.
If you have replaced your battery with new, please see my Topic Warrantee Claims and add comments there viewtopic.php?f=11&t=1186&p=12670#p12670

For more info on why EV suffer problems checkout this YouTube link.
From 5yrs ago but a good informative video
Transport Evolved

And to learn more about how you could inject more life into an ailing 12V check this out.
Desulphating device
Skip to last 2 batteries
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Parker87
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Post by Parker87 » Sat Jul 16, 2022 9:31 am

A quick bump on this topic please.
I'm collecting my E next week and I've been in the habit of keeping the 12V on my current EV topped up in situ by using a Ctek 5.0 charger. I'd like to do the same with my E but am wondering where people are attaching the Negative clip of their chargers? Any advice would be much appreciated. TIA.

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milligoon
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Post by milligoon » Sat Jul 16, 2022 11:11 am

Get the socket with terminals on for the CTEK then fix to battery they come in a range ring terminal sizes.

No bulky clips then to ping off

https://www.ctek.com/uk/battery-charger ... -eyelet-m6
https://www.ctek.com/uk/battery-charger ... -eyelet-m8
https://www.ctek.com/uk/battery-charger ... eyelet-m10
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